After establishing the accuracy of the FDTD simulation, one can use the numerical results to investigate various aspects of superlens operation that are not described by the steady state transmission coefficient. As mentioned in the discussion of the Fig. REF , the presence of excitons has a limited impact on transmission coefficient; overall, the imaginary part of Cu\(_2\) O permittivity in the spectral range of 2P exciton resonance is of the order of \(Im\)  \(\epsilon \sim 10^{-3}\)  (Fig. REF ) as compared to \(Im\)  \(\epsilon \sim 1\)  in the case of copper (REF ). Therefore, the majority of absorption comes from the metal. On the other hand, it is well known that the surface plasmons-polaritons (SPPs) excited on the metal-dielectric interface are very sensitive to the susceptibility changes in the dielectric. In the case of superlens, these plasmons are excited on both metal-dielectric interfaces and they play a pivotal role in the evanescent field amplification and thus the image formation [1]}, [2]}. At the same time, they tend to distort the image field [3]}.
